THE NUMERICAL CALCULATION OF LOW FREQUENCY ELECTROMAGNETIC TRANSIENT PHENOMENA IN POWER TRANSFORMERS

Abstract

In this article, a transformer model is presented that is applicable to low frequency electromagnetic  transient phenomena of up to 1 kHz. An example of the energization of a no-load transformer  is analyzed. A simplifed analytical approach is presented first. Due to the limitations of this approach,  a numerical approach is introduced for the solution of the stiff differential equations that  describe the transient phenomena. In both cases, algorithms have been developed for generating  the waveforms of the state variables. The results of both algorithms are compared to the results  of the MATLAB/Simulink/Power System Blockset for the analysis of electromagnetic transient  phenomena in electrical energy systems. Developed algorithm with the introduced numerical  approach can be used successfully in other low frequency transient phenomena where the main  subject of analysis is the nonlinear character of the transformer: ferroresonance, load switch-off,  transformer faults etc.